Sulphur_Presentation_With_Frasch_Process.ppt
- 1. Sulphur – The Yellow Non-Metal A brief overview of Sulphur and its importance
- 2. Introduction • Sulphur (Symbol: S, Atomic Number: 16) • Non-metal element with bright yellow color • Found naturally in earth’s crust and atmosphere
- 3. Physical & Chemical Properties • Bright yellow solid, odorless • Atomic mass: 32.06 u • Non-metal, poor conductor of electricity • Insoluble in water, burns with blue flame
- 4. Allotropes of Sulphur • Rhombic Sulphur – Stable at room temp • Monoclinic Sulphur – Stable at ~96°C • Plastic Sulphur – Formed by rapid cooling of molten sulphur
- 5. Occurrence • Found near volcanoes and hot springs • Occurs in minerals: gypsum, pyrite, barite • Extracted from oil and natural gas
- 6. Important Compounds • Sulfur Dioxide (SO₂): used in preservation, bleaching • Sulfuric Acid (H₂SO₄): widely used industrial acid • Hydrogen Sulfide (H₂S): toxic gas with rotten egg smell
- 7. Industrial & Agricultural Uses • Fertilizer production (ammonium sulfate) • Sulfuric acid for batteries, detergents • Used in vulcanization of rubber • Fungicides and insecticides in agriculture
- 8. Environmental Concerns • SO₂ contributes to acid rain • H₂S is hazardous to health • Controlled emissions and scrubbers used
- 9. Fun Facts • Also called 'Brimstone' in ancient texts • Used since ancient times for medicinal purposes • Essential element in human proteins (amino acids)
- 10. Summary • Sulphur is essential in industry, agriculture, and biology • Exists in multiple forms and compounds • Control of sulphur emissions is crucial for the environment
- 11. Production of Sulphur Frasch Process – - Used for underground sulphur deposits. – - Superheated water melts sulphur, air lifts it to surface. – - Produces ~99.5% pure sulphur.
- 12. Claus Process – - Recovers sulphur from H₂S in natural gas and petroleum. – - 2H₂S + SO₂ → 3S + 2H₂O
- 13. Roasting of Sulphide Ores – - Pyrite (FeS₂) roasted to produce SO₂. – - 4FeS₂ + 11O₂ → 2Fe₂O₃ + 8SO₂
- 14. Byproduct Recovery – - Sulphur removed during crude oil refining. – - Recovered as elemental sulphur or processed further.
- 15. Frasch Process – Sulphur Production • 1. Well Drilling: – - A well is drilled into underground sulphur deposits. – - A three-pipe system is installed. • 2. Injection of Superheated Water: – - Water at ~165°C is pumped down the outer pipe. – - It melts the sulphur (melting point ~115°C). • 3. Compressed Air Injection: – - Hot air is sent through the innermost pipe. – - Creates a frothy sulphur-air mixture. • 4. Sulphur Recovery: – - Mixture is pushed up the middle pipe to the surface. – - Sulphur cools and solidifies in storage tanks. • Advantages: – - Produces 99.5% pure sulphur. – - No need for ore mining or chemical treatment. • Limitations: – - High energy use. – - Limited to accessible underground sulphur fields.
- 17. Claus Process – Sulphur Production Overview: • The Claus Process is used to recover elemental sulphur from hydrogen sulfide (H₂S). • Commonly applied in oil refineries and natural gas processing plants.
- 18. • Step 1: Partial Combustion 2H2S+3O2→2SO2+2H2O • About one-third of H₂S is combusted in the presence of oxygen to form sulfur dioxide (SO₂).
- 19. • Step 2: Catalytic Reaction 2H2 S+SO2 →3S+2H2 O • Remaining H₂S reacts with SO₂ in the presence of a catalyst to form elemental sulphur. • Overall Reaction 3H2S+1.5O2→3S+3H2O
- 20. Advantages • Converts toxic H₂S into usable sulphur. • Reduces air pollution and odour. Limitations • Requires high temperatures and catalyst control. • Less effective at low H₂S concentrations.
- 24. Roasting of Sulphide Ores • For zinc 2ZnS+3O2→2ZnO+2SO2 • For iron (in pyrite form) 4FeS2+11O2→2Fe2O3+8SO2
- 25. Roasting of Sulphide Ores • Conversion to Oxide: Roasting converts the sulphide ore into a metal oxide, which is more easily reduced to the pure metal in subsequent steps. • Removal of Sulfur: The process also removes sulfur from the ore in the form of sulfur dioxide, which is then released as a gas. • Impurity Removal: Roasting can also remove other volatile impurities from the ore.
- 26. Key aspects of roasting • Air or Oxygen: Roasting is performed in the presence of excess air or oxygen. • High Temperature: The process requires high temperatures, but typically below the melting point of the ore. • Furnaces: Roasting is typically carried out in furnaces like blast furnaces or reverberatory furnaces.
- 27. OREs
- 29. Process Description • Ore is heated in a furnace (with excess air). • Sulphide ore reacts with oxygen, forming: – Metal oxides (e.g., ZnO, Fe₂O₃) – Sulphur dioxide gas (SO₂), which is removed. • The resulting metal oxide can be reduced further to get the pure metal.
- 30. Purpose of Roasting • Removes volatile impurities. • Converts sulphides to oxides (more easily reduced). • Prepares ores for smelting or reduction.
- 31. Byproduct Recovery • Sulphur is removed during roasting of sulphide ores and crude oil refining. • In roasting, sulphur is released primarily as sulphur dioxide (SO₂). • During crude oil refining, sulphur is separated from hydrocarbons (e.g., through hydrodesulfurization). • Recovered sulphur is either: – Converted to elemental sulphur (e.g., using the Claus Process), or – Processed into sulphuric acid via the Contact Process.
- 32. Purpose and Benefits • Prevents SO₂ emissions, which cause acid rain. • Generates valuable chemicals: elemental sulphur, sulphuric acid. • Ensures compliance with environmental regulations.
- 33. Applications • The main use of sulphur is in the preparation of SO2 which is used in the manufacture of sulphuric acid. • Sulphur is used in the manufacture of carbon disulphate, sodium thiosulphate, gun powder, matches and in fireworks. • Sulphur is used on vulcanization of rubber. Natural rubber is soft and sticky. Heating it with sulphur makes it hard non-sticky and more elastic. This process of heating of natural rubber with sulphur is known as vulcanization. • Sulphur is used as fungicide and insecticide in agriculture and as a disinfectant in medicines. • Sulphur is used in ointments for curing skin diseases. • Sulphur is used in beauty parlours to give specific shapes to the hair.